GHSA-8xv7-89vj-q48c

### Impact
Python's "format" functionality allows someone controlling the format string to "read" objects accessible (recursively) via attribute access and subscription from accessible objects. Those attribute accesses and subscriptions use Python's full blown `getattr` and `getitem`, not the policy restricted `AccessControl` variants `_getattr_` and `_getitem_`. This can lead to critical information disclosure.

`AccessControl` already provides a safe variant for `str.format` and denies access to `string.Formatter`. However, `str.format_map` is still unsafe.

Affected are all users who allow untrusted users to create `AccessControl` controlled Python code and execute it.

### Patches
A fix will be introduced in the versions 4.4, 5.8 and 6.2.

### Workarounds
There are no workarounds.

### References
https://github.com/zopefoundation/RestrictedPython/security/advisories/GHSA-xjw2-6jm9-rf67 describes the corresponding problem for `RestrictedPython`.